Wild bird chase? {Lots of people would like to deflect  blame from industrialized poultry farming and role of people – about time someone said – whoa – how about some science?}

But not so fast, say experts like David Stallknecht, PhD, of the University of Georgia’s College of Veterinary Medicine, and Michele Carstensen, PhD, wildlife health program supervisor in the Minnesota Department of Natural Resources (DNR). They point out, among other things, that migratory birds don’t migrate from west to east or from north to south in late winter.

“This could all have been from wild birds—nobody can say it’s impossible,” said Stallknecht. “But we do need some proof. . . . People seem to be willing to accept things without a whole lot of proof.”

He said it is unknown how the H5N8 strain that gave rise to H5N2 reached North America. Noting that the H5N2 outbreaks in British Columbia marked the “index case” or first appearance of the virus, he said, “How much proof do we have of wild bird involvement with that virus in North America? None.”

Referring to the mixing of H5N8 with North American viruses, he said, “Why do we make the jump to wild ducks to explain this? Reassortment could also occur in a backyard flock of domestic ducks after a more direct introduction [of H5N8] via people.” He suggested that travelers could possibly have brought the virus to Canada from Asia.

He cautioned that this is “pure speculation,” but added that the idea that wild birds introduced the parental H5N8 virus to North America is also speculative. “It is based on circumstantial evidence that is rapidly becoming accepted dogma.”

Carstensen said the notion that wild birds could have brought the H5N2 virus from Minnesota to Missouri is “beyond me. . . . They [migratory birds] go from south to north this time of year.” Arkansas and Kansas, on the other hand, are close enough to migratory-bird wintering grounds to make a connection with wild birds more plausible, she added.

There could be “totally different causes” for the outbreaks in Minnesota and the more southerly states, Carstensen suggested.

via Role of wild birds in US H5N2 outbreaks questioned | CIDRAP.